The present invention relates to a part reusing method of allowing a designer to smoothly reuse past design results in a control design configuration tool used to develop control software such as a system control program for a control system.
A control design configuration tool is a software system for designing a control system, converting a design result into a data form usable in a controller, and outputting the converted data. FIG. 8 shows a control design example on such a control design configuration tool. A designer displays, in an editing window or editing sheet 81 of a display, basic functional parts (to be referred to as control parts hereinafter) 82, 83, and 84 corresponding to input/output (I/O) points such as analog input (AI) parts and analog output (AO) parts and control points such as PID parts. The designer then defines connection relationships 85 and 86 of input/output terminals 82b, 83a, 83b, 84a of these control parts to design a control system and create control software.
At this time, if the past design results constituted by a plurality of control parts can be effectively reused, the efficiency of the design jobs can be improved, and hence the productivity can be improved.
In many conventional control design configuration tools, even if basic functional parts (control parts) corresponding to the minimum functional units of the controller and the set values (data) of the respective control parts are reusable, the design results constituted by a combination of a plurality of control parts cannot be reused.
In order to solve this problem, an attempt has been made to represent a design result having a specific function in the form of software IC parts on a configuration tool. More specifically, a design result (reusable parts) constituted by a plurality of control parts is defined as a black box, and input/output data associated with the function of this black box are represented by the input/output terminals of the black box.
In the form of software IC parts described above, it is difficult to obtain information serving as a clue to determine whether to apply the design result and associated with connection destinations of the input/output terminals of the reusable parts (black box). For this reason, a design result to be reused cannot be smoothly searched. That is, it is difficult to determine destination parts to be connected to the input/output terminals of the reusable parts and the attributes of the destination parts by simply observing the constituent parts of the design result to be reused. Therefore, inappropriate basic control parts may be connected to reusable parts in design due to the shortage of information associated with connections between the input/output terminals, thus degrading efficiency of design jobs.
Conventionally, in order to obtain such information, an instruction manual attached to the design result representing software IC parts, and a document describing information associated with connections between the input/output terminals must be separately searched, thus requiring a long search time.
Even if connection destination parts connected to the design result to be reused have set values or data common to the parts connected to the reusable parts, no means is provided to share these data. The same data must be input again at the reuse destination. As a result, the data input becomes time-consuming and cumbersome, and input errors may degrade the design quality.